Yes, however it is not a 100% fit. If you look towards the bottom of a P99 you'll see that the grip is recessed where the Walther banner is. The S&W doesn't share this indention. While the grip fits, it leaves a lip of 1/16" from the indentation. That said, I had a S&W size small on mine for a month or so while waiting for a Walther one.I noticed that the SW99 backstraps are checked unlike the P99 straps which have dots. Does anyone know if they are interchangeable?